Motor-pump unit



Oct. 16, 1956 1 2,766,595

MOTOR-PUMP UNIT Filed April 6, 1954- 2 Sheets-Sheet l Ta'g.1

/ INVENTOR Louis Gailloud/ ATTORNEY Oct. 16, 1956 GAlLLOUD 2,766,625

MOTOR-PUMP UNIT Filed April 6, .1954 2 Sheets-SheeL E ATTORNEY United States Patent MOTOR-PUMP UNIT Louis Gailloud, Chatelaine-Vernier, Switzerland, assignor to Ateliers des Charmilles S. A., Geneva, Switzerland, a Swiss company Application April 6, 1954, Serial No. 421,395

Claims priority, application Switzerland September 25, 1953 Claims. (Cl. 103-87) The present invention has for its subject a pump and driving motor-pump unit of the type in which the rotor of the driving motor is bathed by the liquid to be pumped and is separated from the stator of the motor by a casing mounted to form a lateral extension of the body of the pump, the shaft of the pump wheel driven by the motor being tubular and turning about a stationary spindle which serves to support it, the body of the pump having a removable end cover located opposite the pump wheel, said end cover enabling the rotor of the motor to be inserted in position within the motor casing and the pump wheel within the body part of the pump, one of the ends of the stationary shaft being supported in the said end cover and the other end in the bottom of the casing separating the rotor and stator of the motor.

Motor-pump units of this character are used particularly in central heating installations for boosting water circulation.

The motor-pump unit according to the invention is characterised in that the end of the stationary shaft carried by the separating casing is provided with means enabling it, on the one hand, to be secured in position, without radial play from the interior of the said casing, in such a manner as to ensure effective fluidtightness of the latter and on the other hand, permitting the mounting and dismounting of the said stationary shaft through the opening normally covered by the said removable end cover.

A number of forms of construction of a motor-pump unit according to the invention are shown diagrammatically and by way of example in the accompanying drawings, wherein:

Fig. 1 is a view in sectional side elevation of a first form of construction.

Fig. 2 is a sectional view on a larger scale of a portion of the form of construction according to Fig. 1.

Figs. 3 and 4 are views showing details.

Fig. 5 is a sectional elevational view of a part of a second form of construction.

Fig. 6 shows a modification of the second form of construction of Fig. 5.

Figs. 7 to 11 show detail views of four other forms of construction.

The motor-pump unit shown in Figs. 1 to 4 comprises an asynchronous motor formed by a rotor 1 and a stator 2. The rotor 1 is secured upon a tubular shaft 3 to the end of which is secured the pump wheel 4.

The rotor 1 is enclosed by a casing 5, secured in a fiuidtight manner to an annular flange 6 of the pump body 7, so as to form a lateral axial extension of the latter. The casing 8 of the motor is itself secured to the pump body 7 by screws 9 and is co-axial with the casing 5.

The tubular shaft 3 driven by the motor forms the driving shaft of the pump, and it is mounted to turn about a stationary shaft 10, and being supported on said stationary shaft by sleeve bearings 11 and 12.

The pump body 7 is provided on its outer end with an opening 13, closed by an end cover 14 secured against the said opening by screws 15.

The stationary shaft 10 is supported at one of its ends in the end cover 14 and at its other end in the bottom of the interior of the separating casing 5.

In the case shown in Figs. 1 and 2, the end cover 14 is provided, at its centre, with a bore 16 coned at its inner end, in which engages a member 17 formed with resilient sectors 18 forming a chuck-like clamp, within which engages the end 19 of the shaft 10. Said resilient sectors are provided with external bearing surfaces 20 bearing on the conical end part of the bore 16. The outer end of the part 17 is screw-threaded for reception of a nut 21. Screwing on of the nut 21 produces the tightening of the said sectors 18 on to the end of the stationary spindle 10. It is to be observed that the end 19 of the shaft 10 engages within the bore 22 of the part 17, in which bore is located a coiled spring 23. The spring 23 is interposed between the end 19 of the shaft and the bottom of the bore 22 and tends to force the bearing surfaces 20 of the clamping end of member 17 against their conical seat.

The other end 24 of the stationary shaft, which is supported by the separating casing 5, engages with a sleeve 25 fixed in the bottom end of the said casing 5. The end 24 is provided with two slots 26 at right angles to one another, intersecting the shaft over a portion of its length into four sectors, in such a manner as to impart thereto a predetermined resiliency so that the said shaft 10 engages with a predetermined degree of friction in the sleeve 25.

The means for securing the shaft 10 in the separating casing 5 on the one hand, and in the plug 14 on the other hand also facilitate the mounting and dismantling of the motor-pump unit. Thus after removal of the end cover 14, it is possible to withdraw the rotary parts of the unit comprising the rotor of the motor, the tubular driving shaft 3 and the pump wheel through the opening 13 in the end of the pump casing. Furthermore the stationary shaft 10 can also be withdrawn readily from its seating through the opening 13.

As the stationary shaft 10 is secured to the separating casing 5 at the inside of the latter, the fiuidtightness of the said casing 5 is unimpared, no screw or other fixing means passing therethrough.

It will readily be understood that the part 17, forming the clamp for fixing the end 19 of the stationary shaft, is capable of being moved axially in the direction towards the pump wheel 4 after removing the nut 21, so as to be capable thereafter of being rotated by the rotary parts of the unit and thus permitting the direction of rotation of the latter to be observed. As shown in Figs. 1 and 2, the part 17 may for this purpose be provided with projections 27 and the rotary part of the group with projections 28, the said projections 27 and 23 forming coupling means for the part 17 and the rotary parts of the unit which, when the part 17 is moved towards the pump wheel 4 against the action of the spring 23, produces driven rotation of the said part 17 by the rotor 1.

This feature of construction enables the direction of rotation of the moving parts of the motor-pump unit to be ascertained readily whilst avoiding escape of liquid to the exterior. To avoid risk of entrainment in rotation of the stationary shaft 10 with the rotary parts of the unit due to possible axial movement of the part 17 when ascertaining the direction of rotation of the rotary parts, a transverse pin 58 mounted in the sleeve 25, as shown in broken lines in Fig. 1, engages in the slotted part 26 of the shaft 10 and prevents any rotation thereof.

The motor-pump unit is also provided with various means for the purification of that part of the liquid intended to lubricate the bearings 11 and 12. In a motorpump unit of this character, a portion of the liquid supplied to the pump escapes between the disc 29 of the pump wheel and the adjacent part 30 of the body of the pump. This diverted liquid reaches an annular chamber 31, bounded, on the one hand, by the disc 29 of the pump wheel constituting the passive face thereof and, on the other hand, by the end cover 14. From the chamber 31 the liquid flows in a centripetal manner towards the stationary shaft and thence between the stationary and tubular shafts 10 and 3 in such a manner as to lubricate the bearings 11 and 12.

It is of importance that the liquid serving for the lubrication of the bearings is free from any solid matter or other impurity. In the construction according to the invention, the lubricating liquid is subjected to four successive phases of purification before reaching the bearings 11 and 12. The liquid is first subjected to a first centrifuging during its flow through a passage defined by the peripheral edge 32 of the pump wheel, and by the part 30 of the pump body (see Fig. 4). The elimination of a first category of impurities by this first centrifuging of the lubricating liquid is assisted by the provision of a chamfer 33 on the said part 30 of the pump body. It will be observed that the passage bounded by the edge 32 and the part 30 is of a section which varies according to the axial position of the rotary assembly of the unit and it also takes a part in the maintenance of axial stability or equilibrium of the said rotary assembly. The liquid contained in the annular chamber 31 and which is entrained in rotation by the disc 29, is subjected to a new centrifuging which produces a second phase of purification thereof. A passage 34 is provided to aflord communication between this chamber 31 and the suction side of the pump. The passage 34 which is also a factor providing axial stability or equilibrium of the rotary assembly of the unit also serves for elimination of impurities centrifuged or accumulating in the chamber 31.

The end cover 14 is provided, at its central portion, with a collar 35 of annular form, the edge of which determines, in conjunction with the central part of the disc 29 forming the passive face of the pump wheel, a second passage 36 of variable cross-sectional dimensions. The passage 36 tends to open as the first passage of variable cross-sectional dimensions between the edge 32 and the part 30 of the body of the pump tends to close. Said second passage of variable cross-sectional dimensions also assists in the maintenance of axial stability or equilibrium of the rotary assembly of the unit. Lubrieating liquid, during its flow through the passage 36, is subjected to a third phase of purification by centrifuging.

The end of the tubular shaft 3, adjacent the pump wheel, is closed by a washer 37, the outer edge of the opening of which has a conical chamfer 38. The conical chamfer 38 tends to produce, during the passage of lubricating liquid between the washer 39 and the stationary shaft 10, a fourth phase of purification by centrifuging the liquid (see Fig. 2).

This series of successive phases of purification for the liquid enable the lubricating liquid to be freed from all solid matter otherwise dangerous for the bearings, even when the liquid being pumped convoys large quantities of such solid matter. Such solid matter, dangerous to bearings, include particularly sand, deposits of rust or filings or solder which may occur in the passages, or even of scale which may be deposited on the inner walls of the said passages.

In the second form of construction shown in Fig. 5, the stationary shaft 10 of the unit is supported at the bottom of the separating casing in the same manner as in the first described form of construction, that is by means of a sleeve 25 secured to the interior of the bottom of the casing 5. The end 19 of the spindle 10, on the other hand, instead of being held in a clamp secured to the end cover 14, has a screwed end portion 39 screwed into a threaded bore 40 in the said end cover 14. It will be understood that with this second form of construction observation of the direction of rotation cannot be made in the manner set out above in connection with the construction of Figs. 1 and 2.

Fig. 6 shows a modification of the second form of construction of Fig. 5, according to which the end 19 of the spindle is extended sufiiciently so as to project to the outside of the end cover 14, which is in this case provided with a smooth bore 41. A nut 42, screwed on the threaded end part 39 of the spindle 1t), enables the spindle 16 to be locked relative to the end cover 14. In this construction the end 24 of the stationary spindle may be supported in the casing 5 in the same manner as in the first two embodiments described above.

Fig. 7 shows still another construction in which the fixing of the end 24 of the spindle 1t) stationary in the separating casing 5 is also effected by using a sleeve 25, secured to the interior of the bottom of the said casing 5. However, sleeve 25 in this case i threaded internally and is of internal cone form at one end as shown at 43. The end 2 of the spindle 10 has a threaded extreme part 44, followed by a conical part 45. The spindle 10 is screwed into the sleeve 25 and its conical part 45, by co-operation with the conical end 43 of the sleeve, ensures the centering of the spindle in the separating casing 5.

In the form of construction shown in Fig. 8, the end 24 of the spindle 10 is coned as shown at 46, the cone 46 engaging in the conical end 47 of a sleeve 48 secured to the interior of the bottom of the casing 5. The end 19 of the spindle 10 in this case is held tightly in the central part of the end cover 14 by a clamp of a. type such as the clamp 17 shown in Fig. 1. The said clamp as shown is formed by a part 49 having resilient sectors 50 of external conical shape cooperating with a conical end 51 of a central bore 52 provided in the end cover 14. The end 19 is capable of sliding within the interior of the part 49 against the action of a compression spring 53 located between the end of the spindle 10 and the rear end of the part 49 forming the clamp.

The spring 53 thus tends, on the one hand, to hold the end 24 of the spindle 10 centred in the sleeve 48 and, on the other hand, to produce a tightening contraction of the sectors 50, forming the jaws of the clamp, against the end 19 of the spindle 10.

In the two forms of construction shown in Figs. 9 to 11, the stationary spindle is secured, at its end 24, to a support 54 which resiliently engages in the separating casing.

5 in the direction towards its bottom for ensuring the centering of the end of the spindle in the latter. In the form of construction shown in Figs. 9 and 10, the support 54 is formed by a disc having three resilient peripheral parts 55 enabling the support to be forced into the casing 5.

In the construction of Fig. 11, the support 54 is also formed by a disc having a slightly conical peripheral edge 56. The part 57 of the separating casing adjacent the periphery of the bottom thereof is also slightly conical, so that the disc is centered in the said casing 5.

In these last two forms of construction, the end 19 of the stationary shaft may be supported in the end cover 14 in the same manner, for example, as in the construction shown in Fig. 8.

It will be understood that in all forms of construction according to Figs. 5 to 11, the liquid serving for the lubrication of the bearings is subjected, as in the first form of construction according .to Figs. 1 to 4, to a number of successive phases of purification.

It will readily be seen that all the securing means for the end 24 of the stationary shaft 10 in the separating casing 5, while ensuring radial centering without play of the said shaft, also afford a guaranty of effective fluidtightness of the casing, as well as easy dismantling and extraction of the said stationary shaft through the opening 13 provided in the end of the body of the pump opposite the pump wheel 4.

It will further be seen that this construction of motorpump unit enables the rotor 1 and the stator 2 to be dismantled from the motor without it being necessary to separate the unit as a Whole from the installation in which it has been incorporated. In fact, after removing the end cover 14, the entire rotary assembly of the unit can be withdrawn fro-m its housing, that is to .say from the separating casing 5 and from the pump body 7. Similarly by removing the screws 9, the motor casing 8 to gether with the stator 2 of the motor can be detached from the pump body, without it being necessary for this purpose to separate the body of the pump from the installation of which it forms a part.

I claim:

1. A motor-pump unit of the kind in which the rotor of the motor is bathed by liquid to be pumped, comprising a motor casing and a pump body connected with one another, a separating casing constituting a lateral extension of the pump body and separating the rotor and the stator of the motor, a tubular shaft driven by the rotor of the motor, a pump wheel carried by said tubular shaft, a stationary spindle extending through and supporting said tubular shaft, a removable end cover on the pump casing facing this pump wheel, permitting removal and insertion of the rotor of the motor, the tubular shaft and the pump wheel, a first support at the bottom end of and wholly inside the said separating casing for one end of said stationary spindle and a further support on the said end cover for the other end of said stationary spindle.

2. A motor-purnp unit as claimed in claim 1 wherein the first support is in the form of a sleeve carried by the bottom of and inside the separating casing and forming a friction fit over one end of the stationary spindle, and the further support is in the form of :a clamp carried by the end cover and engaged over and clamping the other end of the stationary spindle.

3. A motor-pump unit as claimed in claim 1 in which the removable end cover has a bore of cone shape at one end, and the further support for the other end of the stationary spindle is in the form of :a sleeve of cone shape and split at one end, located in the bore provided in the said end cover, said sleeve being screw threaded at its end remote from the split cone-shaped end and carrying a nut adapted to draw the said sleeve into the said bore to tighten the split cone-shaped end on the end of the stationary spindle.

4. A motor-pump unit as claimed in claim 1 in which the removable end cover has a bore of cone shape at one end, and the further support for the other end of the stationary spindle is in the form of a sleeve of cone shape and split at one end, located in the bore provided in the said end cover, said sleeve being screw threaded at its end remote from the split cone-shaped end and carrying a nut adapted to draw the said sleeve into the said bore to tighten the split cone-shaped end on the end of the stationary spindle and also comprising a projection on the cone-shaped end of said sleeve adapted to make driven engagement with a rotatable part of the unit when the said nut is released and the said sleeve moved axially, to permit observation of the direction of rotation of the said rotatable part.

5. A motor-pump unit as claimed in claim 1 in which the removable end cover has a bore of cone shape at one end, and the further support for the other end of the stationary spindle is in the form of a sleeve of cone shape and split at one end, located in the bore provided in the said end cover, said sleeve being screw threaded at its end remote from the split cone-shaped end and carrying a nut adapted to draw the said sleeve into the said bore to tighten the split cone-shaped end on the end of the stationary spindle, and also comprising an abutment surface within said sleeve and a compression spring between said abutment surface and the adjacent end of the stationary spindle.

6. A motor-pump unit as claimed in claim 1 in which the further support for the other end of said stationary spindle is in the form of a bore in said removable end cover and also comprising a nut screwed on said other end of said stationary spindle to fix said spindle relative to said end cover.

7. A motor-pump unit as claimed in claim 1 in which the stationary spindle has a screw threaded end, and the removable end cover has a screw threaded bore for the reception of a screw threaded end of the stationary spindle.

8. A motor-pump unit as claimed in claim 1, wherein the first support for one end of the stationary spindle comprises an internally threaded sleeve fixed at the bottom of and inside the separating casing for the reception of a threaded end of the stationary spindle, the end of said sleeve being internally coned and the part of the said end of the stationary spindle beyond the screw threaded portion being coned for co-operation with the coned end of the sleeve to centralize the stationary spindle in the said separating casing.

9. A motor-pump unit as claimed in claim 1 in which the stationary spindle has a coned end and the first support for the stationary spindle at the bottom of and inside the separating casing is in the form of a fixed sleeve having a coned free end for the reception of the coned end of the said stationary spindle and the second support for the other end of the stationary spindle is in the form of a coned split sleeve carried by the said separable end cover and receiving the other end of the stationary spindle within it, and comprising an abutment in said sleeve and a compression spring disposed between said abutment and the adjacent end of the stationary spindle and adapted to tighten the split sleeve on to the stationary spindle and to urge the coned end of the stationary spindle into the said fixed sleeve constituting the said first support.

10. A motor-pump unit as claimed in claim 1 in which the first support for one end of the stationary spindle comprises an element receiving that end of the stationary spindle and resiliently engaging in the said separating casing in the direction towards the bottom thereof.

11. A motor-pump unit as claimed in claim 1 in which the first support for one end of the stationary spindle in the form of a disc receiving that end of the stationary spindle and having three yielding parts symmetrically distributed about the periphery of the disc, said disc resiliently engaging in the said separating casing in the direction towards the bottom end thereof and a further support on the said end cover for the other end of said stationary spindle.

12. A motor-pump unit as claimed in claim 1 in which the separating casing has a conical part at its free end, the first support for one end of the stationary spindle comprises a disc receiving that end of the stationary spindle and resiliently engaging in the conical part at the free end of the said separating casing in the direction towards the bottom thereof.

13. A motor-pump unit according to claim 1, wherein passages are provided for circulation of liquid to lubricate the bearings and flowing into the tubular shaft, and in which the axial stable equilibrium of the rotary parts is ensured by one of the passages and of variable crosssection bounded in part by a peripheral edge of the pump wheel, and a part of the pump body surrounding the pump wheel having a chamfer facilitating purification by centrifuging the liquid passing through the said passage of variable cross-section, an annular chamber being provided between the end cover and the adjacent face of the pump wheel, in which chamber the body of liquid contained therein is itself driven in rotation by the pump wheel, and produces a second centrifuging of impurities contained in the liquid, another passage providing communication between the lower part of said annular chamher and the suction side of the pump to permit emergence of impurities which have been centrifuged into said chamber. 7

14. A motor-pump unit according to claim 13, wherein the said end cover is provided with a collar of which the edge determines, in conjunction with the central part of the pump wheel face adjacent to the end cover, a second passage of variable cross-sectional dimensions and tend ing to open, if necessary, as the first chamber tends to close, in which passage is produced a third. purification phase by centrifuging of the lubricating liquid for the bearings which flows in a centripetal manner against the face of the wheel adjacent to the end cover to the interior of the tubular shaft of the unit.

15. A motor-pump unit according to claim 13, char- References Cited in the file of this patent UNITED STATES PATENTS 2,261,915 Korte et al. Nov. 4, 1941 2,646,001 Ray July 21, 1953 2,681,010 Hilken June 15, 1954 FOREIGN PATENTS 289,479 Switzerland July 1, 1953 

